This invention relates to pneumatic pump actuating mechanism, and, particularly, to the use of the aforesaid mechanisms with a sewing machine motor in threading the needle in a sewing machine.
Threading the sewing needle in a sewing machine must be performed periodically during the sewing operation. This being a very tedious task, various devices have been provided to assist the operator, which include pneumatic threading assists. In the past, the air pressure, or vacuum, used with these devices was supplied either external to the sewing machine or by a self-contained electric pump housed within or on the sewing machine frame. In either case, a motor separate from the sewing machine motor is required to operate the pump. Since needle threading is necessarily performed while the stitch forming instrumentalities are stationary, there exists a needless motor redundancy which increase the expense and the probability of failure in providing the pneumatic needle threading assist feature.